U.S. patent application number 14/626473 was filed with the patent office on 2015-08-20 for lenses with graded photochromic, molds and methods of making same.
The applicant listed for this patent is QSpex Technologies, Inc.. Invention is credited to Dionisio Cruz, Jessica L. Gettings, Leslie F. Stebbins, Kai C. Su.
Application Number | 20150231839 14/626473 |
Document ID | / |
Family ID | 53797326 |
Filed Date | 2015-08-20 |
United States Patent
Application |
20150231839 |
Kind Code |
A1 |
Su; Kai C. ; et al. |
August 20, 2015 |
LENSES WITH GRADED PHOTOCHROMIC, MOLDS AND METHODS OF MAKING
SAME
Abstract
Certain aspects of the invention are directed to a photochromic
lens having a graded or variable tint, methods and molds of making
the same. In one embodiment, the photochromic lens includes a lens
element having a upper portion and a lower portion; and a
UV-absorbing layer formed of a UV-absorbing material on a surface
of the lens element, such that the UV-absorbing material is more
concentrated at the lower portion of the lens element and less
concentrated at the upper portion, thereby allowing more UV light
to strike the photochromic at the upper portion of the lens element
than at the lower portion. The lens element comprises a
photochromic composition.
Inventors: |
Su; Kai C.; (Alpharetta,
GA) ; Stebbins; Leslie F.; (Roswell, GA) ;
Cruz; Dionisio; (Buford, GA) ; Gettings; Jessica
L.; (Johns Creek, GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
QSpex Technologies, Inc. |
Alpharetta |
GA |
US |
|
|
Family ID: |
53797326 |
Appl. No.: |
14/626473 |
Filed: |
February 19, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61942246 |
Feb 20, 2014 |
|
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|
Current U.S.
Class: |
351/159.61 ;
249/114.1; 264/1.7; 427/162 |
Current CPC
Class: |
B29D 11/00865 20130101;
B29D 11/00009 20130101; B29D 11/00923 20130101; B29L 2011/0066
20130101; G02C 7/02 20130101; G02C 7/105 20130101; G02C 7/102
20130101; G02B 5/23 20130101; B29D 11/00653 20130101; G02B 5/208
20130101; G02B 1/14 20150115 |
International
Class: |
B29D 11/00 20060101
B29D011/00; G02C 7/02 20060101 G02C007/02; G02C 7/10 20060101
G02C007/10; G02B 1/14 20060101 G02B001/14; B29C 39/02 20060101
B29C039/02 |
Claims
1. A photochromic lens, comprising: a lens element having a upper
portion and a lower portion; and a UV-absorbing layer formed of a
UV-absorbing material on a surface of the lens element, such that
the UV-absorbing material is more concentrated at the lower portion
of the lens element and less concentrated at the upper portion,
thereby allowing more UV light to strike the photochromic at the
upper portion of the lens element than at the lower portion.
2. The photochromic lens of claim 1, wherein the lens element
comprises a photochromic composition.
3. The photochromic lens of claim 1, wherein the UV-absorbing layer
has a thickness that is uniform from a bottom to a top of the
UV-absorbing layer, or decreases gradually from a bottom to a top
of the UV-absorbing layer.
4. The photochromic lens of claim 1, further comprising a first
coating formed over the UV-absorbing layer, wherein the first
coating is a hard coat.
5. The photochromic lens of claim 1, further comprising a second
coating formed on the lens element, wherein the UV-absorbing
material is applied to the second coating on the lens element.
6. The photochromic lens of claim 5, wherein the second coating is
a tintable hard coat.
7. The photochromic lens of claim 4, further comprising a hard coat
layer formed on the lens element, wherein the second coating is
applied over the hard coat layer on the lens element, and the
UV-absorbing material is applied to the second coating overlaying
the hard coat layer.
8. The photochromic lens of claim 1, wherein the lens element
comprises a lens blank including a semi-finished lens, a finished
lens, or a wafer lens that is a portion of the lens.
9. The photochromic lens of claim 8, wherein the lens element is
made of glass, or plastic.
10. A method of forming a photochromic lens, comprising: providing
a lens element having a upper portion and a lower portion; and
forming a graded or variable tint on a surface of the lens element
by applying a UV-absorbing material to the lens element, wherein
the UV-absorbing material is more concentrated at the lower portion
of the lens element and less concentrated at the upper portion,
thereby allowing more UV light to strike the photochromic at the
upper portion of the lens element than at the lower portion.
11. The method of claim 10, wherein the lens element comprises a
photochromic composition.
12. The method of claim 10, wherein the UV-absorbing layer has a
thickness that is uniform from a bottom to a top of the
UV-absorbing layer, or decreases gradually from a bottom to a top
of the UV-absorbing layer.
13. The method of claim 10, further comprising forming a first
coating over the UV-absorbing layer, wherein the first coating is a
hard coat.
14. The method of claim 10, further comprising forming a second
coating on the lens element, wherein the UV-absorbing material is
applied to the second coating on the lens element.
15. The method of claim 14, wherein the second coating is a
tintable hard coat.
16. The method of claim 14, further comprising forming a hard coat
layer on the lens element, wherein the second coating is applied
over the hard coat layer on the lens element, and the UV-absorbing
material is applied to the second coating overlaying the hard
coat.
17. The method of claim 10, where the step of applying the
UV-absorbing material to the lens element comprises applying the
UV-absorbing material to a coating on a lens mold that is used to
cast or mold the photochromic lens.
18. The method of claim 17, wherein the UV-absorbing material is
applied to a front mold such that that UV-absorber is at or near
the front of the photochromic lens.
19. The method of claim 17, wherein the UV-absorbing material is
applied to a back mold, so that the photochromic lens made
therefrom has a graded or gradient darkening when exposed to
UV-light from a backside of the photochromic lens.
20. The method of claim 10, wherein the lens element comprises a
lens blank including a semi-finished lens, a finished lens, or a
wafer lens that is a portion of the lens.
21. A mold for forming a photochromic lens, comprising: a front
mold and a back mold, each mold defining an optical surface; a
first coating on the optical surface of the front mold or the back
mold, wherein the first coating is a hard coat; and a UV-absorbing
layer formed of a UV-absorbing material on the first coating, such
that the UV-absorbing material is more concentrated at a lower
portion of the UV-absorbing layer and less concentrated at a upper
portion of the UV-absorbing layer.
22. The mold of claim 21, wherein the UV-absorbing layer has a
thickness that is uniform from a bottom to a top of the
UV-absorbing layer, or decreases gradually from a bottom to a top
of the UV-absorbing layer.
23. The mold of claim 21, further comprising a second coating
formed on the UV-absorbing layer.
24. The mold of claim 21, wherein the hard coat is a tintable hard
coat.
25. The mold of claim 21, further comprising a buffer coat
overlaying the hard coat.
26. The mold of claim 21, wherein in use, the front mold and the
back mold are positioned to define a cavity therebetween in which a
lens element is cast to form the photochromic lens.
27. The mold of claim 26, wherein when cured, the coating and the
UV-absorbing layer are transferred to the photochromic lens having
a graded or variable tint, thereby allowing more UV light to strike
the photochromic at the upper portion of the photochromic lens than
at the lower portion of the photochromic lens.
28. The mold of claim 26, wherein the lens element comprises a
photochromic composition.
29. The mold of claim 21, wherein the front and back molds are
formed of plastic.
30. A method of forming a photochromic lens using the mold of claim
21, wherein the front mold and the back mold are positioned to
define a cavity therebetween, comprising: casting a lens element in
the cavity; and curing the cast lens element to transfer the first
coating and the UV-absorbing layer to the lens element to form the
photochromic lens, so that the photochromic lens allows more UV
light to strike the photochromic at the upper portion of the
photochromic lens than at the lower portion of the photochromic
lens.
31. The method of claim 30, wherein the lens element comprises a
photochromic composition.
32. A method of forming a photochromic lens, comprising: providing
a mold having a front mold and a back mold, each mold defining an
optical surface, wherein the front mold and the back mold are
adapted to define a cavity therebetween; forming a first coating on
the optical surface of the front mold or the back mold, wherein the
first coating is a hard coat; forming a UV-absorbing layer with a
UV-absorbing material on the coating, such that the UV-absorbing
material is more concentrated at a lower portion of the
UV-absorbing layer and less concentrated at a upper portion of the
UV-absorbing layer; casting a lens element in the cavity; and
curing the cast lens element to transfer the first coating and the
UV-absorbing layer to the lens element to form the photochromic
lens, so that the photochromic lens allows more UV light to strike
the photochromic at the upper portion of the photochromic lens than
at the lower portion of the photochromic lens.
33. The method of claim 32, further comprising forming a second
coating on the UV-absorbing layer.
34. The method of claim 32, wherein the hard coat is a tintable
hard coat.
35. The method of claim 32, further comprising forming a buffer
coat overlaying the hard coat.
36. The method of claim 32, wherein the lens element comprises a
photochromic composition.
37. The method of claim 32, wherein the front and back molds are
formed of plastic
38. The method of claim 32, wherein the UV-absorbing layer has a
thickness that decreases gradually from a bottom to a top of the
UV-absorbing layer.
39. The method of claim 32, wherein the curing step is performed
with UV-Visible light.
40. A photochromic lens having a upper portion and a lower portion,
comprising a graded or variable tint, such that the upper portion
of the lens darkens when exposed to UV light, and the lower portion
of the lens remains clear at all times.
41. A mold for forming the photochromic lens of claim 40.
42. A photochromic lens having a upper portion and a lower portion,
comprising a graded or variable tint, such that the lens darkens in
a gradient of clear to dark from the lower portion to the upper
portion.
43. A mold for forming the photochromic lens of claim 42.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of,
pursuant to 35 U.S.C. .sctn.119(e), U.S. provisional patent
application Ser. No. 61/942,246, filed Feb. 20, 2014, entitled
"METHOD FOR MANUFACTURING LENSES WITH GRADED PHOTOCHROMIC AND
LENSES MANUFACTURED THEREWITH", by Kai C. Su, Leslie F. Stebbins,
Dionisio Cruz and Jessica L. Gettings, which is incorporated herein
in its entirety by reference.
[0002] Some references, which may include patents, patent
applications and various publications, are cited and discussed in
the description of this invention. The citation and/or discussion
of such references is provided merely to clarify the description of
the present invention and is not an admission that any such
reference is "prior art" to the invention described herein. All
references cited and discussed in this specification are
incorporated herein by reference in their entireties and to the
same extent as if each reference were individually incorporated by
reference.
FIELD OF THE INVENTION
[0003] The invention relates generally to lenses, and more
particularly to lenses with graded photochromic, molds and methods
of making same.
BACKGROUND OF THE INVENTION
[0004] The background description provided herein is for the
purpose of generally presenting the context of the present
invention. The subject matter discussed in the background of the
invention section should not be assumed to be prior art merely as a
result of its mention in the background of the invention section.
Similarly, a problem mentioned in the background of the invention
section or associated with the subject matter of the background of
the invention section should not be assumed to have been previously
recognized in the prior art. The subject matter in the background
of the invention section merely represents different approaches,
which in and of themselves may also be inventions. Work of the
presently named inventors, to the extent it is described in the
background of the invention section, as well as aspects of the
description that may not otherwise qualify as prior art at the time
of filing, are neither expressly nor impliedly admitted as prior
art against the present invention.
[0005] Photochromic lenses are typically made by evenly applying a
photochromic coating to a plastic ophthalmic lens or by
incorporating a photochromic compound in the lens matrix. The
photochromic lens darkens when exposed to UV light, allowing the
lenses to function as sunglasses, then fades when the UV light is
removed.
[0006] One common problem associated with the conventional
photochromic lenses is long fade time, in which when the wearer
goes from outdoors in the sun to indoors, where the light is
dimmer, the lenses do not fade immediately, making vision
difficult. In addition, the conventional photochromic lenses may
also make outdoor reading difficult.
[0007] Therefore, a heretofore unaddressed need exists in the art
to address the aforementioned deficiencies and inadequacies.
SUMMARY OF THE INVENTION
[0008] One of the objectives of the present invention is to provide
a gradient photochromic lens that solves the aforementioned
deficiencies and inadequacies by remaining clear in the lower (or
bottom) portion of the photochromic lens. It would also facilitate
outdoor reading and other activities in which clear eyesight is
crucial.
[0009] In one aspect of the present invention, the photochromic
lens includes a lens element having a upper portion and a lower
portion; and a UV-absorbing layer formed of a UV-absorbing material
on a surface of the lens element, such that the UV-absorbing
material is more concentrated at the lower portion of the lens
element and less concentrated at the upper portion, thereby
allowing more UV light to strike the photochromic at the upper
portion of the lens element than at the lower portion. In one
embodiment, the lens element comprises a photochromic
composition.
[0010] In one embodiment, the UV-absorbing layer has a thickness
that is uniform from a bottom to a top of the UV-absorbing layer,
or decreases gradually from a bottom to a top of the UV-absorbing
layer.
[0011] In one embodiment, the photochromic lens further comprises a
first coating formed over the UV-absorbing layer, where the first
coating is a hard coat.
[0012] In another embodiment, the photochromic lens may also
include a second coating formed on the lens element, where the
UV-absorbing material is applied to the second coating on the lens
element, and the second coating is a tintable hard coat.
[0013] In yet another embodiment, the photochromic lens may further
include a hard coat layer formed on the lens element, where the
second coating is applied over the hard coat layer on the lens
element, and the UV-absorbing material is applied to the second
coating overlaying the hard coat layer.
[0014] In one embodiment, the lens element comprises a lens blank
including a semi-finished lens, a finished lens, or a wafer lens
that is a portion of the lens, where the lens element is made of
glass, or plastic.
[0015] In another aspect, the present invention relates to a method
of forming a photochromic lens. In one embodiment, the method
includes providing a lens element having a upper portion and a
lower portion; and forming a graded or variable tint on a surface
of the lens element by applying a UV-absorbing material to the lens
element, wherein the UV-absorbing material is more concentrated at
the lower portion of the lens element and less concentrated at the
upper portion, thereby allowing more UV light to strike the
photochromic at the upper portion of the lens element than at the
lower portion. In one embodiment, the lens element comprises a
photochromic composition.
[0016] In one embodiment, the UV-absorbing layer has a thickness
that is uniform from a bottom to a top of the UV-absorbing layer,
or decreases gradually from a bottom to a top of the UV-absorbing
layer.
[0017] In one embodiment, the method further comprises forming a
first coating over the UV-absorbing layer, wherein the first
coating is a hard coat.
[0018] In another embodiment, the method also comprises forming a
second costing on the lens element, where the UV-absorbing material
is applied to the second coating on the lens element, and the
second coating is a tintable hard coat.
[0019] In yet another embodiment, the method may also comprise
forming a hard coat layer on the lens element, where the second
coating is applied over the hard coat layer on the lens element,
and the UV-absorbing material is applied to the second coating
overlaying the hard coat.
[0020] In one embodiment, the step of applying the UV-absorbing
material to the lens element comprises applying the UV-absorbing
material to a coating on a lens mold that is used to cast or mold
the photochromic lens. In one embodiment, the UV-absorbing material
is applied to a front mold such that that UV-absorber is at or near
the front of the photochromic lens. In another embodiment, the
UV-absorbing material is applied to a back mold, so that the
photochromic lens made therefrom have a graded or gradient
darkening when exposed to UV-light from a backside of the
photochromic lens.
[0021] In one embodiment, the lens element comprises a lens blank
including a semi-finished lens, a finished lens, or a wafer lens
that is a portion of the lens.
[0022] In yet another aspect, the present invention relates to a
mold for forming a photochromic lens. In one embodiment, the mold
has a front mold and a back mold, each mold defining an optical
surface; a first coating on the optical surface of the front mold
or the back mold, where the first coating is a hard coat; and a
UV-absorbing layer formed of a UV-absorbing material on the first
coating, such that the UV-absorbing material is more concentrated
at a lower portion of the UV-absorbing layer and less concentrated
at a upper portion of the UV-absorbing layer. In one embodiment,
the hard coat is a tintable hard coat. In one embodiment, the mold
may have a buffer coat overlaying the hard coat. In one embodiment,
the front and back molds are formed of plastic.
[0023] In use, the front mold and the back mold are positioned to
define a cavity therebetween in which a lens element is cast to
form the photochromic lens. When cured, the coating and the
UV-absorbing layer are transferred to the photochromic lens having
a graded or variable tint, thereby allowing more UV light to strike
the photochromic at the upper portion of the photochromic lens than
at the lower portion of the photochromic lens. In one embodiment,
the lens element comprises a photochromic composition.
[0024] In one embodiment, the UV-absorbing layer has a thickness
that is uniform from a bottom to a top of the UV-absorbing layer,
or decreases gradually from a bottom to a top of the UV-absorbing
layer.
[0025] In one embodiment, the mold further has a second coating
formed on the UV-absorbing layer.
[0026] In addition, in certain embodiments, the mold for forming
the photochromic lens may have only the front mold as disclosed
above. In use, instead of a back mold, a pre-formed lens or a
portion of a lens forms the back side of the lens cavity. When
cured, the coating and the UV-absorbing layer are transferred to
the photochromic lens having a graded or variable tint, and the
pre-formed lens or portion of a lens is attached thereto.
[0027] In a further aspect, the present invention relates to a
method of forming a photochromic lens using the mold as disclosed
above, where the front mold and the back mold are positioned to
define a cavity therebetween. In one embodiment, the method
comprises casting a lens element in the cavity; and curing the cast
lens element to transfer the first coating and the UV-absorbing
layer to the lens element to form the photochromic lens, so that
the photochromic lens allows more UV light to strike the
photochromic at the upper portion of the photochromic lens than at
the lower portion of the photochromic lens. The lens element
comprises a photochromic composition.
[0028] In one aspect, the present invention relates to a method
forming a photochromic lens. In one embodiment, the method
comprises providing a mold having a front mold and a back mold,
each mold defining an optical surface, where the front mold and the
back mold are adapted to define a cavity therebetween; forming a
first coating on the optical surface of the front mold or the back
mold, wherein the first coating is a hard coat; forming a
UV-absorbing layer with a UV-absorbing material on the coating,
such that the UV-absorbing material is more concentrated at a lower
portion of the UV-absorbing layer and less concentrated at a upper
portion of the UV-absorbing layer; casting a lens element in the
cavity; and curing the cast lens element to transfer the first
coating and the UV-absorbing layer to the lens element to form the
photochromic lens, so that the photochromic lens allows more UV
light to strike the photochromic at the upper portion of the
photochromic lens than at the lower portion of the photochromic
lens. In one embodiment, the hard coat is a tintable hard coat.
[0029] In one embodiment, the method further comprises forming a
second coating formed on the UV-absorbing layer.
[0030] In another embodiment, the method also comprises forming a
buffer coat overlaying the hard coat.
[0031] In one embodiment, the lens element comprises a photochromic
composition. In one embodiment, the front and back molds are formed
of plastic.
[0032] In one embodiment, the UV-absorbing layer has a thickness
that decreases gradually from a bottom to a top of the UV-absorbing
layer.
[0033] In one embodiment, the curing step is performed with
UV-Visible light.
[0034] In another aspect, the present invention relates to a
photochromic lens having a upper portion and a lower portion,
comprising a graded or variable tint, such that the upper portion
of the lens darkens when exposed to UV light, and the lower portion
of the lens remains clear at all times.
[0035] In yet another aspect, the present invention relates to a
photochromic lens having a upper portion and a lower portion,
comprising a graded or variable tint, such that the lens darkens in
a gradient of clear to dark from the lower portion to the upper
portion.
[0036] In certain aspects, the present invention relates to a mold
for forming the photochromic lens as disclosed above.
[0037] These and other aspects of the present invention will become
apparent from the following description of the preferred embodiment
taken in conjunction with the following drawings, although
variations and modifications therein may be affected without
departing from the spirit and scope of the novel concepts of the
disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The accompanying drawings illustrate one or more embodiments
of the disclosure and together with the written description, serve
to explain the principles of the disclosure. Wherever possible, the
same reference numbers are used throughout the drawings to refer to
the same or like elements of an embodiment.
[0039] FIGS. 1A-1D show photochromic lenses according to various
embodiments of the present invention.
[0040] FIGS. 2A-2D show photochromic lenses according to various
embodiments of the present invention.
[0041] FIGS. 3A-3D show photochromic lenses according to various
embodiments of the present invention.
[0042] FIGS. 4A-4D show a mold and a process of making a
photochromic lens therewith according to one embodiment of the
present invention.
[0043] FIGS. 5A-5B show photochromic lenses according to various
embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0044] The present disclosure will now be described more fully
hereinafter with reference to the accompanying drawings, in which
exemplary embodiments of the invention are shown. This invention
may, however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein. Rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. Like reference numerals
refer to like elements throughout.
[0045] The terms used in this specification generally have their
ordinary meanings in the art, within the context of the invention,
and in the specific context where each term is used. Certain terms
that are used to describe the invention are discussed below, or
elsewhere in the specification, to provide additional guidance to
the practitioner regarding the description of the invention. For
convenience, certain terms may be highlighted, for example using
italics and/or quotation marks. The use of highlighting has no
influence on the scope and meaning of a term; the scope and meaning
of a term is the same, in the same context, whether or not it is
highlighted. It will be appreciated that the same thing can be said
in more than one way. Consequently, alternative language and
synonyms may be used for any one or more of the terms discussed
herein, nor is any special significance to be placed upon whether
or not a term is elaborated or discussed herein. Synonyms for
certain terms are provided. A recital of one or more synonyms does
not exclude the use of other synonyms. The use of examples anywhere
in this specification including examples of any terms discussed
herein is illustrative only, and in no way limits the scope and
meaning of the invention or of any exemplified term. Likewise, the
invention is not limited to various embodiments given in this
specification.
[0046] It will be understood that when an element is referred to as
being "on" another element, it can be directly on the other element
or intervening elements may be present therebetween. In contrast,
when an element is referred to as being "directly on" another
element, there are no intervening elements present. As used herein,
the term "and/or" includes any and all combinations of one or more
of the associated listed items.
[0047] It will be understood that, although the terms first,
second, third etc. may be used herein to describe various elements,
components, regions, layers and/or sections, these elements,
components, regions, layers and/or sections should not be limited
by these terms. These terms are only used to distinguish one
element, component, region, layer or section from another element,
component, region, layer or section. Thus, a first element,
component, region, layer or section discussed below could be termed
a second element, component, region, layer or section without
departing from the teachings of the disclosure.
[0048] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising", or "includes"
and/or "including" or "has" and/or "having" when used in this
specification, specify the presence of stated features, regions,
integers, steps, operations, elements, and/or components, but do
not preclude the presence or addition of one or more other
features, regions, integers, steps, operations, elements,
components, and/or groups thereof.
[0049] Furthermore, relative terms, such as "lower" or "bottom",
"upper" or "top", and "left" and "right", may be used herein to
describe one element's relationship to another element as
illustrated in the Figures. It will be understood that relative
terms are intended to encompass different orientations of the
device in addition to the orientation depicted in the Figures. For
example, if the device in one of the figures is turned over,
elements described as being on the "lower" side of other elements
would then be oriented on "upper" sides of the other elements. The
exemplary term "lower", can therefore, encompasses both an
orientation of "lower" and "upper", depending of the particular
orientation of the figure. Similarly, if the device in one of the
figures is turned over, elements described as "below" or "beneath"
other elements would then be oriented "above" the other elements.
The exemplary terms "below" or "beneath" can, therefore, encompass
both an orientation of above and below.
[0050] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and the present
disclosure, and will not be interpreted in an idealized or overly
formal sense unless expressly so defined herein.
[0051] As used herein, "around", "about" or "approximately" shall
generally mean within 20 percent, preferably within 10 percent, and
more preferably within 5 percent of a given value or range.
Numerical quantities given herein are approximate, meaning that the
term "around", "about" or "approximately" can be inferred if not
expressly stated.
[0052] As used herein, the terms "comprise" or "comprising",
"include" or "including", "carry" or "carrying", "has/have" or
"having", "contain" or "containing", "involve" or "involving" and
the like are to be understood to be open-ended, i.e., to mean
including but not limited to.
[0053] The description will be made as to the embodiments of the
present invention in conjunction with the accompanying drawings. In
accordance with the purposes of this invention, as embodied and
broadly described herein, this invention, in certain aspects,
relates to a method of creating a graded or variable tint on a
photochromic lens, a photochromic lens made by the method, and a
photochromic lens mold for making the photochromic lens.
[0054] In one embodiment, the photochromic lens is made such that
the top of the lens darkens when exposed to UV light, but the
bottom of the lens remains clear at all times. In another
embodiment, the lens darkens such that there is a gradient of clear
to dark from bottom to top.
[0055] By gradient is meant graded or variable where there is a
variation in the darkness of the lens which may be quantitatively
expressed as a percentage (%) of light transmittance. For example,
where the light transmittance at the lens bottom is high, such as
about 100%, or about 98%, or about 95%, the light transmittance at
the upper portion of the lens are less than about 100%, or less
than about 98%, or less than about 95%. That is, the light
transmittance at the bottom of the lens is more than at the upper
portion of the lens, and intermediate percent light transmittance
is allowed at any intermediate regions of the lens between the
upper and lower. In some cases, only two zones, that is of high and
low transmittance are in the gradient lens. In other aspects, there
may be an indeterminate number of gradations of light transmittance
so as to provide a smooth continuation between high light
transmittance at the bottom of the lens and low transmittance at
the top of the lens.
[0056] Referring to FIGS. 1A-1D, four photochromic lenses are
respectively shown according to four embodiments of the present
invention.
[0057] As shown in FIGS. 1A and 1C, the photochromic lens includes
a lens element 110 having a upper portion 112 and a lower portion
114. The lens element 110 usually comprises a photochromic
composition. The photochromic lens further includes a UV-absorbing
layer 140 (140') formed of a UV-absorbing material 145 on a surface
113 of the lens element 110.
[0058] Further, the photochromic lens may also have a first coating
150 formed over the UV-absorbing layer 140 (140'), as shown in
FIGS. 1B and 1D. The first coating 150 can be a hard coat.
[0059] According to the invention, the UV-absorbing layer 140
(140') is formed such that the UV-absorbing material 145 is more
concentrated at the lower portion 114 of the lens element 110 and
less concentrated at the upper portion 112, which allows more UV
light to strike the photochromic at the upper portion 112 of the
lens element 110 than at the lower portion 114. Accordingly, the
photochromic lens has a graded or variable tint.
[0060] In one embodiment, the UV-absorbing material 145 is all
concentrated at the lower portion 114 of the lens element 110, and
no UV-absorbing material 145 is concentrated at the upper portion
114 of the lens element 110. For such a photochromic lens, the
upper portion 112 of the lens darkens when exposed to UV light,
while the lower portion 114 of the lens remains clear at all
times.
[0061] In another embodiment, the concentration of the UV-absorbing
material 145 is gradually reduced from the lower portion 114 of the
lens element 110 to the upper portion 114 of the lens element 110.
For this photochromic lens, it darkens in a gradient of clear to
dark from the lower portion 114 to the upper portion 112 of the
lens.
[0062] In certain embodiments, the UV-absorbing layer 140 has a
thickness, D, that is uniform from a bottom 144 to a top 142 of the
UV-absorbing layer 140, as shown in FIGS. 1A and 1B, where the
UV-absorbing material 145 is more concentrated at the lower portion
114 of the lens element 110 and less concentrated at the upper
portion 112.
[0063] In certain embodiments, the thickness D of the UV-absorbing
layer 140' decreases gradually from a bottom 144 to a top 142 of
the UV-absorbing layer 140', as shown in FIGS. 1C and 1D, where the
concentration of the UV-absorbing material 145 is gradually reduced
from the lower portion 114 of the lens element 110 to the upper
portion 114 of the lens element 110.
[0064] FIGS. 2A-2D show four photochromic lenses according to
another four embodiments of the present invention, respectively. In
addition to the structures of the photochromic lenses shown in
FIGS. 1A-1D, the photochromic lenses shown in FIGS. 2A-2D also
include a second coating 130 formed on the lens element 110, where
the UV-absorbing material 145 is applied to the second coating 130
on the lens element 110. In certain embodiments, the second coating
130 is a tintable hard coat.
[0065] FIGS. 3A-3D show four photochromic lenses according to yet
another four embodiments of the present invention, respectively. In
addition to the structures of the photochromic lenses shown in
FIGS. 2A-2D, the photochromic lenses shown in FIGS. 3A-3D further
include a hard coat layer 120 formed on the lens element 110, where
the second coating 130 is applied over the hard coat layer 120 on
the lens element 110, and the UV-absorbing material 145 is applied
to the second coating 130 overlaying the hard coat layer 120.
[0066] In certain embodiments, the lens element comprises a lens
blank including a semi-finished lens, a finished lens, or a wafer
lens that is a portion of the lens. The lens element is made of
glass, or plastic.
[0067] In one aspect of the invention, the method of forming a
photochromic lens includes providing a lens element having a upper
portion and a lower portion; and forming a graded or variable tint
on a surface of the lens element by applying a UV-absorbing
material to the lens element, where the UV-absorbing material is
more concentrated at the lower portion of the lens element and less
concentrated at the upper portion, thereby allowing more UV light
to strike the photochromic at the upper portion of the lens element
than at the lower portion. In one embodiment, the lens element
comprises a photochromic composition.
[0068] As discussed above, the UV-absorbing layer has a thickness
that can be uniform from a bottom to a top of the UV-absorbing
layer, or decreases gradually from a bottom to a top of the
UV-absorbing layer.
[0069] Further, the method comprises forming a first coating over
the UV-absorbing layer, where the first coating is a hard coat.
[0070] In addition, the method may also comprise forming a second
costing on the lens element, where the UV-absorbing material is
applied to the second coating on the lens element, and the second
coating is a tintable hard coat.
[0071] Moreover, the method may comprise forming a hard coat layer
on the lens element, where the second coating is applied over the
hard coat layer on the lens element, and the UV-absorbing material
is applied to the second coating overlaying the hard coat.
[0072] In certain embodiments, the step of applying the
UV-absorbing material to the lens element comprises applying the
UV-absorbing material to a coating on a lens mold that is used to
cast or mold the photochromic lens. In one embodiment, the
UV-absorbing material is applied to a front mold such that that
UV-absorber is at or near the front of the photochromic lens. In
certain embodiments, the UV-absorbing material is applied to a back
mold, so that the photochromic lens made therefrom have a graded or
gradient darkening when exposed to UV-light from a backside of the
photochromic lens.
[0073] Referring to FIGS. 4A-4D, a mold and a process for forming a
photochromic lens are shown according to one embodiment of the
present invention. In one embodiment, the mold includes a front
mold 211 having an optical surface 212, and a back mold 215 having
an optical surface 217. In this exemplary embodiment, the front
mold 211 has a concave surface 212 with a first curvature, and the
back mold 215 has a convex surface 217 with a second curvature, as
shown in FIGS. 4A-4B. The first curvature and the second curvature
are substantially identical or different. If both the first
curvature and the second curvature are identical, the concave
surface 212 of the front lens mold 210 is substantially
complementary to the convex surface 217 of the back mold 215. Each
of the front mold 211 and the back mold 215 is formed of glass,
plastic or metal. In one embodiment, the front mold 211 and the
back mold 215 are formed of plastic. The lens mold may further have
a gasket 219 such that when assembled, the gasket 219 seals the
lens cavity (space) defined between the front mold 211 and the back
mold 215.
[0074] Further, a first coating 250 is formed on the optical
surface 212 or 217 of the front mold 211 or the back mold 215. In
this embodiment, the first coating 250 is formed on the optical
surface 212 of the front mold 211, as shown in FIG. 4C. The first
coating 250 is a hard coat. In one embodiment, the hard coat is a
tintable hard coat. In one embodiment, a polystyrene spectacle lens
mold is spin-coated with a hard coat and then a buffer coat
(Ebecryl 8402+UV-Cure Initiators) overlaying the hard coat.
[0075] Moreover, a UV-absorbing layer 240 is formed of a
UV-absorbing material on the first coating 250. The UV-absorbing
material is more concentrated at a lower portion 244 of the
UV-absorbing layer 240 and less concentrated at an upper portion
242 of the UV-absorbing layer 240, as shown in FIG. 4D. In certain
embodiments, the UV-absorbing layer 240 has a thickness that can be
uniform from a bottom to a top of the UV-absorbing layer 240, or
decreases gradually from a bottom to a top of the UV-absorbing
layer 240.
[0076] In one embodiment, a bottom section of the coated mold is
dipped into a heated solution of a UV Absorber in water (5%
Lowilite.RTM. 20S in water, Addivant.TM., Danbury, Conn.). The mold
is then blown dry.
[0077] In use, the front mold 211 and the back mold 215 are
positioned to define a space (lens cavity) therebetween in which a
photochromic lens composition 210 is cast to form the photochromic
lens. A gasket, spacer or other means may be used to seal the lens
cavity. When cured, the coating 250 and the UV-absorbing layer 240
are transferred to the photochromic lens having a graded or
variable tint, thereby allowing more UV light to strike the
photochromic at the upper portion of the photochromic lens than at
the lower portion of the photochromic lens. In one embodiment, the
cast lens element 210 is cured by UV-Visible light in the mold
assembly for about 5 minutes. The photochromic lens is demolded and
annealed at about 80.degree. C. for about 20 minutes. The formed
photochromic lens has the same structure as that shown in FIG.
2B.
[0078] Then, the lens element 110 of lens-forming fluid is cast
into the cavity. The lens-forming fluid within the cavity is cured
so as to form a photochromic lens having a graded or variable tint.
Finally, the photochromic lens is obtained by removing the front
mold 211, the back mold 215 and the gasket.
[0079] In certain embodiments, the lens element is a formulation
that may be cured or polymerized to form a lens. For example, the
formulation could be a mixture of monomers, polymers, oligomers and
so forth such that when cured (polymerized), a hardened lens is
formed. Lens formulations having reactive acrylate or methacrylate
functional groups that can be cured by UV and/or visible light may
be used. Heat curable formulations are another non-limiting example
lens element formulation. When using plastic molds, the heat
stability of the mold must be taken into consideration in selecting
the type of lens formulation and the curing conditions so that the
lens forming surface of the mold is not damaged by the casting and
curing processes.
[0080] In certain embodiments, for a photochromic lens, the lens
element formulation may contain one or more photochromic dyes,
which will provide a so-called "in mass" photochromic lens after
curing. Alternatively, a photochromic layer may be coated over the
mold that has been previously coated with hard coat, optional
buffer coat, and UV absorbing gradient layer. In this case, a
non-photochromic lens element formulation may then be cast into the
photochromic layered mold set and cured to provide a gradient
photochromic lens. The mold may also contain a transferable
anti-reflective coating and/or a polarized film, so that gradient
photochromic lenses having anti-reflective and/or polarizing
properties may be prepared by using the inventive concepts herein
described.
[0081] In addition, in certain embodiments, the mold for forming
the photochromic lens may have only the front mold as disclosed
above and is devoid of a back mold. In use, instead of a back mold,
a pre-formed lens or a portion of a lens forms the back side of the
lens cavity. When cured, the coating and the UV-absorbing layer are
transferred to the photochromic lens having a graded or variable
tint, and the pre-formed lens or portion of a lens is attached
thereto.
[0082] According to certain embodiments of the invention, the
UV-absorbing material 340 (340') can also be applied to a back
mold, so that the photochromic lens made therefrom have a graded or
gradient darkening when exposed to UV-light from a backside of the
photochromic lens element 310, as shown in FIGS. 5A-5B.
[0083] In one aspect, the present invention relates to a method of
forming a photochromic lens using the mold as disclosed above,
where the front mold and the back mold are positioned to define a
cavity therebetween. In one embodiment, the method comprises
casting a lens element in the cavity; and curing the cast lens
element to transfer the first coating and the UV-absorbing layer to
the lens element to form the photochromic lens, so that the
photochromic lens allows more UV light to strike the photochromic
at the upper portion of the photochromic lens than at the lower
portion of the photochromic lens. The lens element comprises a
photochromic composition.
[0084] In another aspect, the present invention relates to a method
forming a photochromic lens. The method comprises the following
steps: At first, a mold having a front mold and a back mold is
provided, where each mold defines an optical surface, and the front
mold and the back mold are adapted to define a cavity
therebetween.
[0085] Then, a first coating is formed on the optical surface of
the front mold or the back mold, where the first coating is a hard
coat. In one embodiment, the hard coat is a tintable hard coat.
[0086] Next, a UV-absorbing layer is formed of a UV-absorbing
material on the coating, such that the UV-absorbing material is
more concentrated at a lower portion of the UV-absorbing layer and
less concentrated at an upper portion of the UV-absorbing
layer.
[0087] Further, a lens element including a photochromic composition
is cast in the cavity.
[0088] Finally, the cast lens element is cured so as to transfer
the first coating and the UV-absorbing layer to the lens element to
form the photochromic lens. As such, the photochromic lens allows
more UV light to strike the photochromic at the upper portion of
the photochromic lens than at the lower portion of the photochromic
lens.
[0089] In one embodiment, the method further comprises forming a
second coating formed on the UV-absorbing layer.
[0090] In another embodiment, the method also comprises forming a
buffer coat overlaying the hard coat.
[0091] In one embodiment, the curing step is performed with
UV-Visible light.
[0092] In yet another aspect of the present invention, the
photochromic lens having a upper portion and a lower portion,
comprises a graded or variable tint, such that the upper portion of
the lens darkens when exposed to UV light, and the lower portion of
the lens remains clear at all times.
[0093] In a further aspect of the present invention, the
photochromic lens having a upper portion and a lower portion,
comprises a graded or variable tint, such that the lens darkens in
a gradient of clear to dark from the lower portion to the upper
portion.
[0094] In certain aspects, the present invention relates to a mold
for forming the photochromic lens as disclosed above.
[0095] In sum, the invention recites, among other things, a
photochromic lens having a graded or variable tint, methods and
molds of making the same. The photochromic lens includes a
UV-absorbing layer formed of a UV-absorbing material on a surface
of the lens element, such that the UV-absorbing material is more
concentrated at the lower portion of the lens element and less
concentrated at the upper portion, thereby allowing more UV light
to strike the photochromic at the upper portion of the lens element
than at the lower portion. Accordingly, the upper portion of the
lens darkens when exposed to UV light and the lower portion of the
lens remains clear at all times, or the lens darkens in a gradient
of clear to dark from the lower portion to the upper portion when
exposed to UV light.
[0096] The foregoing description of the exemplary embodiments of
the invention has been presented only for the purposes of
illustration and description and is not intended to be exhaustive
or to limit the invention to the precise forms disclosed. Many
modifications and variations are possible in light of the above
teaching.
[0097] The embodiments were chosen and described in order to
explain the principles of the invention and their practical
application so as to enable others skilled in the art to utilize
the invention and various embodiments and with various
modifications as are suited to the particular use contemplated.
Alternative embodiments will become apparent to those skilled in
the art to which the present invention pertains without departing
from its spirit and scope. Accordingly, the scope of the present
invention is defined by the appended claims rather than the
foregoing description and the exemplary embodiments described
therein.
* * * * *